Automatic train-stop.



J. H. PRALL.

AUTOMATIG TRAIN STOP. APPLICATION FILED SEPT. 9. 1913.

Patented Feb. 23, 1915.

2 BEBETS-SHEET 1.

INVENTOR ATTORNEYS THE NORRIS PETERS C0 PHOTO-LITHO.. WASHING MN. [1. r

J. H. PRALL.

AUTOMATIC TRAIN STOP.

APPLICATION FILED SEPT. 9. 1913.

Patented Feb. 23, 1915.

' BET 2.

WITNESSES 30 E I 5 lNl/E/VTOR MO (fflM/S'J' /7f P5444 By W ATTORNEYS THE NORRIS PETERS 60., PHOTOLITHO" WASHINGmN. D c.

JAMES HENRY PRALL, 0F LACONA, IOWA.

AUTOMATIC TRAIN-STOP.

Specification of Letters Patent.

Patented Feb. 23, 1915.

Application filed September 9, 1913. Serial No. 788,815.

To alt whom it may concern:

Be it known that I, JAMES H. PRALL, a citizen of the United States, and a resident of Lacona, in the county of IWarren and State of Iowa, have invented a new and Improved Automatic Train-Stop, of which the following is a full, clear, and exact description.

My invention relates to a novel means for automatically bringing railway trains to a stop by applying the brakes through the medium of co-acting track and car elements.

The inventionresides more especially in the track devices, which comprise a trip adapted to be thrown into position to be engaged by an element on the train, the trip being mounted to be thrown into 0perative or inoperative position, and to yield to a train passing in either direction, while affording sufficient resistance to actuate the train devices, the train devices being usually in the form of means to relieve the air pressure in the train pipe of air brake systems.

In connection with the rock shaft or rod on which the track, trip is mounted, a looking device is employed, which is interposed in the connections between the said rod and a semaphore or other signal and arranged to lock the rod of the tracktrip either in the operative or inoperative position.

Thev invention .will be particularly explained in the specific description follow- Iteference is to be had to the accompanying drawings forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure 1 is a front elevation of a train stop embodying my invention, a portion of a car being conventionally shown in transverse section; Fig. 2 is a longitudinalsection; Fig. 3 is a vertical section of the looking device to lock the. rod of the track trip; Fig. l is an elevation of said locking device, the view being taken at right angles 3; \Fig. 5 is a detail cross sectional View of one form of valve that may be employed for relieving the pressure in the air pipe; Fig. 6 is an end view with parts in section, showing another form of valve; Fig. 7 is a detail inverted view of a portion of the rod of the track trip and certain elements associated therewith to be hereinafter referred to.

In carrying out my invention in accordto Fig.

ance with the illustrated example, a relief valve 10 is mounted on -the engine or car 11, being supported on abracket 12 or its equivalent, and. communicates by a branch 13 with the train pipe 14 of an air brake system. Arranged in connection with the valve 10 is a valve-controlling means, here illustrated as a frame 15, having an upper crossbar journaled to rock in the bracket 12 at one side and a bracket 12 at the other side, the lower cross bar'15 being positioned to be engaged and tripped by the track trip 16, hereinafter further referred to. The upper memberjof the valve-controlling element 15, in the form shown in Figs. 2 and 5, is in fixed relation to a cylindrical valve 10 having ports 10 adapted to be turned into or out of register with the branch 18 and an outlet passage 10.

In the arrangement shown in Fig. v6, the valve-controlling trip on the car, designated by the numeral 15*, is indirectly connected with the valve 10, for opening and closing the latter, said valve being in all respects the same as that shown in Fig. 5, except that its stem 10 has a crank arm 17 connected by a link 18 with a rocker arm 19,

turn connected with the trip 15, which is in the form of a suitable frame hung in the hanger bracket 12*. In both instances the contact of the train trip 15 or 15 with the track trip 16, will result in the rocking of the train trip and the opening of the valve to relieve the pressure in the train pipe and apply the brake in the well known manner.

The tracktrip the latter being in 16 is rock shaft or rod 20, which may be supported in suitable bearings at the inner end, the rod in the illustrated example being indicated as extending transversely through the rails 21 and having bearings therein, but it will be understood that any other suitable supporting means may be provided. At the outer end the rod may extend into the hollow base 22 of a semaphore or like signal. I

In connection with the outer end of the rod 20 and the rod or any equivalent element 23 extending upwardly to the signal 23 I provide alocking means to hold the rod in either of two positions to dispose the track trip 16 vertically in operative position, or lowered through an angle of approximately 90 degrees to the inoperative position. The locking means for the rod fixedly secured to a is so related to thelatter that the track trip, when vertical, may yield to a contact with the train on a tram passing in either '2 direction without affecting the locking means.

The locking means comprises two co-acting elements 24:, 25, mounted to rock on different centers, one center being the axis of the rod 20, and having arms (hereinafter referred to) that move through intersecting trip 16 in the operative or inoperative posi-' tions. The arms on the rocking members 24.,

25, interlock upon the member 24: and trip rod 20 reaching the limit of their rocking movement in either direction.

The element 24: in the illustrated construction is in the form of a bar parallel with the rod 20, and is formed with end flanges 26 on the under side through which the rod loosely passes. Coiled on the rod between the flanges 26, is a torsion spring 27, each end of the spring passing through a staple or equivalent guide 28 on said rod, the extreme end of the spring being deflected, a's at 29, and disposed adjacent to a lug 30 or other stop on the locking element 24, the purpose of which arrangement will appear from the following: The upper rocking element 25 isin the form of a bar, trunnions 31 of which have bearings in the sides of the signal -base 22 or other'support. The element 2 1 has opposite lateral arms 32, and the element 25 has oppositelateral arms 33 disposed above the first mentioned arms. A suitable connection, as by a link 34?, is made between one arm 33' and the element 23' eX- tending to the semaphore.

The mounting of the respective locking elements to rock on different centers, in effect, mounts the respective arms 32, 33 eccentrically, the outer ends thereof describing intersecting arcs. The arms 32 lie adjacent to the arms 33, and a movement of the signal rod 23 will therefore cause the element 25 to rock, and the frictional engagement of said arms with the arms 32, will rock the shaft 20 to move the track trip 16 into or out of operative position. Upon the rod 20 reaching the limit of itsrocking movementin either direction the arm 32 at that side of the rod 20 in the direction in which the latter is rocked, will contact with the lo' )tt(" m"22 of the signal base 22, or with any equivalent stop limiting the movement of the parts. At the same time the mentioned arm 32 will interlock with the adja cent arm 33, said arms having moved through intersecting arcs and being formed to have interlocking engagement. In the example shown, an inner latching shoulder 35 is formed on each arm 32, at the upper side, behind which shoulder the end of the adjacent arm 33 will engage when the arm 32 is arrested after reaching the limit of its movement, the locked position of the parts being best. shown in Fig. 3;

N twithstanding the locking of the ele} men'ts24, 25, the rod 20 may be turned in either direction response to contact between thetrack'tri'plfi and the enginepilot, the spring 27 constituting a yielding con nection between the rod and the locking means. lVhen' the rod is" rocked'iri one direction, one spring arm 29 willengagew'ith the adjacent stop'men'iber" 30 of the locking element'2-1, thereby holding that end of the spring against turning, but the oppositeend 29 will be free'to move away from its adja' cent stop 30 and will be carried around by engagement of its guidestaple 28. Thus the spring will be placed under torsional strain by a rocking of the rod 20 in either direction: relatively to the lockedelement 24.

It follows therefore, that upon the pilot of an engine striking the track trip 16, the latter is free to yield in either direction without'affectingtlie locking Ineansor the sema phore, and the spring 27 will immediately restore the trip- 16 to the vertical'position to engage the valve-actuating element 15011 the car. It is to be 'nnderstood thatthe spring 27 is of such strength as to resist rocking movement by the train'element 15, so as to throw the latter andopen" the valve 10.

arrangement is' thata'track trip maybe employed that rises above the path of travelof the "pilot and' still insure the opening of the relief valve. With a track trip risingonly to a height to be cleared by the pilot,"a' train trip 15 must-be employed which will eXtend below the pilot in order to be engaged by the track trip, andthe disadvantage of such an arrangement is that the train trip is liable to be accidentally engaged by ice or like obstruction on the track rising no higher than to be just cleared by the pilot.

Having thus described my invention, I claim'a's newand desire to secure by Letters Patent:

1. In a train stop employing co-acting train and track trips, a rod adaptecl'to rock, a trip thereon, a signal, and means controlled bythe throwing of the signal, to actuate the said rod, andmeans to lockthe said rod in the rocked position, said last mentioned means being releasable by the signal.

2. The-combination of a tra'cktrip, a rod carrying said trip and mounted to rock, a signal, and actuating and locking means for the rod, comprising a rocker element associated with the signal to be actuated in unison therewith, and a rocker element associated with the rod and adapted to be moved by the first rocker element, said rocker elements having arms at opposite sides, adjacent arms of the respective elements being movable in intersecting arcs and adapted to interlock when the trip arm is either in the operative or inoperative position.

3. The combination of a track trip, a rod carrying said trip and mounted to rock, a signal, and actuating and locking means for the rod, comprising a rocker element associated with the signal, to be actuated therewith, and a rocker element associated with the rod, adapted to be moved by the first rocker element, and means for efiecting latched engagement between said elements when the trip arm is in either the operative or inoperative position.

4. In a track trip, a trip arm, a rod carrying said arm and rockable in opposite directions to dispose the arm in either an operative or in an inoperative position, and actuating and locking means for said rod comprising a rocker element, actuating means therefor, a separate rocker element movable in either direction by the first rocker element, and resilient means effecting a connection between the second rocker element and the rod, said rocker elements having latching members movable into engagement in either position of the rod.

5. In a track trip, a rod carrying a trip arm and rockable in opposite directions to dispose the said arm in an operative or inoperative position, a torsion spring on said rod, and locking and actuating means for the rod, comprising a rocker element mounted adjacent to the rod, a second rocker element loose on the rod, and guide members on the rod through which the ends of the torsion spring pass, the terminals of the spring turning laterally and adapted to bear against the locking element on the rod.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

JAMES HENRY PRALL.

Witnesses A. V. PROUDFOOT, W. A. OLIVE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of intents, Washington, D. 0." 

